The present invention relates to a method of calculating a predictive shape of a wire structure, which comes into contact with an obstacle and deforms, using the finite element process and a calculating apparatus and a computer-readable recording medium for the method of calculating a predictive shape of a wire structure.
Usually, plural electric devices are mounted on a vehicle or the like. These electric devices are connected by wire structures called wire harnesses, which are formed by binding plural electric wires or communication lines using binding members such as an insulation lock or protective members such as tapes, as wire materials. As shown in FIG. 1, connectors 2a, 2b, 2c, and 2d, which are connected to electric devices and the like, are attached to respective ends of a wire harness 1. The wire harness 1 has branch wires and various clips 3a, 3b, 3c, and 3d are attached to middle parts of the branch wires. The wire harness 1 further has a branch point 4. Not that, since the branch wires of such a wire harness 1 basically have different numbers and types of wire materials forming the branch wires, the respective branch wires have various thicknesses, lengths, elasticities, rigidities, and the like.
Recently, assuming that such a wire harness is cabled in predetermined sections in a vehicle, as a method of predicting shapes of the wire harnesses, a support system by a computer, in which CAD (Computer Aided Design), CAE (Computer Aided Engineering), and the like are combined, is often used. As a basic method of this support system, a detailed shape of the wire harness, on which thicknesses, lengths, types, and the like of electric wires are reflected, are modeled and rendered using the CAD and, then, necessary data are inputted to predetermined general-purpose CAE as numerical values to cause the CAE to calculate predictive shapes. After evaluating a result of this calculation, predictive shapes are rendered again using the CAD. Then, such a cycle is repeated by a designer, who is proficient in operation of the CAD, the general-purpose CAE, and the like, in a trial and error manner.
Here, references cited in this specification are as described below.
“Matrix Finite Element Process” written by B. Nass, published by the Brain Book Publishing Co., Ltd., Aug. 10, 1978, p. 7 to 15.
“Mode Analysis and Dynamic Design” written by Hitohiko Yasuda, issued by the Corona Co., Ltd., Nov. 10, 1993, p. 54 to 56.
Actually, as shown in FIG. 1, in a section where a wire harness is assumed to be cabled, an obstacle 30 such as an electric device or a projection is often present. Then, a point of contact of the obstacle 30 and the wire harness changes in accordance with deformation of the wire harness. Therefore, it is desirable to calculate a point of contact of the obstacle 30 and the wire harness that changes serially and, then, predict a path of the wire harness with the point of contact reflected on the prediction. However, the wire harness has various numbers and types of wire materials forming the wire harness and various thicknesses, lengths, elasticities, rigidities, and the like of respective wires. Therefore, even if there is no obstacle, it is considered difficult to predict accurate paths of the wire harness. However, a method of predicting a path of a wire harness taking into account such a changing point of contact has not been proposed.
Therefore, in the related design method, there is no way but to predict a path of a wire harness neglecting an obstacle and, then, when an obstacle is present on the predicted path, predict a path again so as to avoid the obstacle or to set a fixed binding point appropriately on the wire harness at the beginning so as to avoid the obstacle and predict a path of the wire harness. Therefore, a method, which can improve this point and predict a path of a wire harness accurately, has been expected.